NEMATODE COMMUNITY RESPONSE TO VARIED PROPORTION OF DECOMPOSING PLANT LITTER

The research objectives were to investigate nematode community response to decomposing plant litter of varying proportions, and to measure the litter decomposition rate. This greenhouse experiments included three treatments of decomposing plant litter with proportions of 30:70, 50:50, and 70:30 (leaf litter to stem-paddy litter, weight to weight), and two controls (commercial organic fertilizers and no-organic matter). We applied the prepared plant litter and organic fertilizers on the surface of the agricultural sandy soil. Soil samples were taken after two, seven, 14, 28, 49, and 77 days to follow nematode temporal changes. Nematodes were assigned to functional groups and family level of a taxon. We used Anova to test the significance of nematode abundance among the treatments, exponential decay model to measure decomposition rates of the plant litter, and canonical correspondence analysis to investigate the correlation of varying plant proportion and nematode community composition. The results showed that nematode functional groups and family did not differ among soils of various plant litter proportions. Bacterivorous Rhabditidae and Cephalobidae, fungivorous Aphelenchidae, and fungivorous-root feeder Tylenchidae inhabited plant litter amended soils. Their abundance, however, differed significantly (p<0.001) and revealed two temporal patterns, i.e., linear (50:50) and unimodal (30:70 and 70:30). No nematodes were observed in organic fertilizer amended soil and no-organic matter soil. Nematode community composition changed over time according to the litter proportion, in which by the end of experiments, community of 50:50 and 30:70 were the least similar (r: 0.57 of axis-1 and 0.54 of axis-2, CPV: 89.06). We concluded that all litter proportions retained similar quality and supported the growth of similar nematode groups. The litter proportion, however, appeared to influence nematode abundance, their temporal patterns, and community compositions

Competitive interaction between two aquatic hyphomycete species and increase in leaf litter breakdown

Aquatic hyphomycete species produce large numbers of conidia which rapidly colonize the leaf litter that falls into rivers during autumn. Our objective was to understand how a species which produces many fewer conidia than another in laboratory conditions can nevertheless be codominant in a natural setting. In microcosm studies with two pioneer dominant species, Flagellospora curvula and Tetrachaetum elegans, inoculated on alder leaves, we first verified that the ratio of the conidium production of both species (6 to 7:1) was inverse to that of individual conidial masses (1:7) as previously described. Calculating the percentage of leaf mass loss that corresponds to 1 mg of conidial mass produced, the combination of the two species produced 2.9-fold more loss than the mean of each species. By contrast, the reproductive biomasses of F. curvula and T. elegans were 5.2- and 2.6-fold lower, respectively. As a result, the conidium production of F. curvula in the combination was only 3.2-fold that of T. elegans instead of 6- to 7-fold in pure culture. In a mixed culture of the two species, T. elegans conidia had a high germination potential (>90%) whereas the proportion of germinated F. curvula conidia was only 50%. Moreover, T. elegans reduced the area on which F. curvula could grow on poor and rich solid media. These results indicate that the dominance of F. curvula conidia in the river may be partly controlled by T. elegans and suggest that a negative interaction between microfungi may have a positive effect on the ecosystem functioning

Optimalisasi Program Kegiatan Ekstrakurikuler untuk Mengembangkan Potensi dan Minat Siswa SMA MBS Zam-Zam Cilongok dalam Bidang Karya Ilmiah

Keterampilan yang perlu dikuasai pada abad 21 antara lain berpikir kritis, kreatif, kolaborasi, dan komunikasi. Kemampuan tersebut hendaknya dapat dikuasai oleh siswa SMA agar kedepannya menjadi terbiasa.&nbsp; Kelompok&nbsp; Karya&nbsp; Ilmiah&nbsp; Remaja&nbsp; (KIR)&nbsp; merupakan&nbsp; salah&nbsp; satu&nbsp; bagian&nbsp; penting&nbsp; dari pendidikan&nbsp; yang&nbsp; membantu&nbsp; siswa&nbsp; mengembangkan&nbsp; keterampilan&nbsp; dan&nbsp; keahlian&nbsp; inti&nbsp; pengetahuan ilmiah serta teknologi. Akan tetapi, kegiatan pada kelompok KIR di SMA Muhammadiyah Boarding School Zam-Zam Cilongok, belum berjalan secara optimal, sehingga perlu dilakukan pelatihan, baik untuk guru pendamping maupun siswanya. Kegiatan knowledge transfer ini dilakukan dengan metode partisipatif dan learning by doing, untuk&nbsp; melatih para guru agar memiliki wawasan dan keterampilan sebagai pendamping KIR, serta melatih siswa untuk melakukan mini-riset secara terbimbing. Data yang diperoleh dianalisis secara deskriptif. Hasilnya menunjukkan bahwa pelatihan untuk para guru telah mampu meningkatkan pengetahuan dan keterampilannya dalam menggali topik untuk menyusun karya ilmiah, baik untuk karya mandiri guru maupun dalam mendampingi siswanya

PELATIHAN ANALISIS MOLEKULER PADA HEWAN DENGAN MARKA RAPD UNTUK MENINGKATKAN KOMPETENSI GURU BIOLOGI SMA/MA KABUPATEN BANYUMAS

Penguasaan materi pembelajaran menjadi salah satu modal bagi seorang guru, karena &nbsp;sangat mendukung kompetensinya. Salah satu materi pembelajaran biologi di SMA adalah tentang Biosistematika Hewan, yang diantaranya mengajarkan tentang keragaman genetik. Pemahaman topik tersebut perlu didukung dengan pemahaman dan keterampilan pendidik dalam melakukan analisis molekuler. Tetapi kemampuan tersebut masih belum dikuasai oleh seluruh guru biologi yang tergabung dalam MGMP Biologi di Kabupaten Banyumas,&nbsp; sehingga atas permintaan kelompok tersebut akan dilakukan pelatihan, agar tugas pokok dan fungsinya tercapai. Pelatihan analisis molekuler dengan marka RAPD untuk MGMP Biologi di Kabupaten Banyumas &nbsp;ini bertujuan untuk&nbsp; meningkatkan&nbsp; kompetensi&nbsp; guru SMA&nbsp; dalam&nbsp; bidang biologi molekuler, guna mendukung pelaksanaan penelitian yang dilakukan oleh guru serta pembelajaran Biosistematik. Metode yang diterapkan adalah partisipatif, yang meliputi persiapan, pelaksanaan pelatihan dan evaluasi kegiatan. Hasilnya menunjukkan bahwa kegiatan dapat berjalan dengan baik dan lancar. Peserta pelatihan sangat antusias selama mengikuti penyampaian materi maupun praktik di laboratorium. Selain itu, juga meningkat pengetahuan dan keterampilannya dalam melakukan karakterisasi molekuler pada ikan. Berkat terselenggaranya pelatihan ini, telah ditandatangani Perjanjian Kerjasama antara Fakultas Biologi dengan MGMP Biologi Kabupaten BanyumasMastery of learning material is one of the assets for a teacher because it supports his competence. One of the biology learning materials in high school is Animal Biosystematics, which includes teaching about genetic diversity. Understanding this topic needs to be supported by educators' understanding and skills in carrying out molecular analysis. However, this ability is still not mastered by all biology teachers who are members of the Biology MGMP in Banyumas Regency, so at the request of this group training will be carried out, so that their main tasks and functions are achieved. Molecular analysis training with RAPD marking for MGMP Biology in Banyumas Regency aims to increase the competency of high school teachers in the field of molecular biology, to support the implementation of research carried out by teachers and Biosystematics learning. The method applied is participatory, which includes preparation, implementation of training, and evaluation of activities. The results show that activities can run well and smoothly. The training participants were very enthusiastic during the delivery of material and practical work in the laboratory. Apart from that, knowledge and skills in carrying out molecular characterization of fish also increase. Thanks to the implementation of this training, a Cooperation Agreement has been signed between the Biology Faculty and the Banyumas Regency Biology MGMP &nbsp

Effects of zinc on leaf decomposition by fungi in streams : studies in microcosms

The effect of zinc on leaf decomposition by aquatic fungi was studied in microcosms. Alder leaf disks were precolonized for 15 days at the source of the Este River, and exposed to different zinc concentrations during 25 days. Leaf mass loss, fungal biomass (based on ergosterol concentration), fungal production (rates of [1-14C]acetate incorporation into ergosterol), sporulation rates and species richness of aquatic hyphomycetes were determined. At the source of the Este River decomposition of alder leaves was fast and 50% of the initial mass was lost in 25 days. A total of 18 aquatic hyphomycete species were recorded during 42 days of leaf immersion. Articulospora tetracladia was the dominant species, followed by Lunulospora curvula and two unidentified species with sigmoid conidia. Cluster analysis suggested that zinc concentration and exposure time affected the structure of aquatic hyphomycete assemblages, even though richness had not been severely affected. Both zinc concentration and exposure time significantly affected leaf mass loss, fungal production and sporulation, but not fungal biomass. Zinc exposure reduced leaf mass loss, inhibited fungal production and affected fungal reproduction by either stimulating or inhibiting sporulation rates. The results of this work suggested zinc pollution might depress leaf decomposition in streams due to changes in the structure and activity of aquatic fungi.Fundação para a Ciência e a Tecnologia (FCT) – Programa Operacional “Ciência, Tecnologia, Inovação” (POCTI) - POCTI/34024/BSE/2000

Diversity and functions of leaf-decaying fungi in human-altered streams

1. Stream conditions have been evaluated using leaf breakdown, and aquatic hyphomy- cetes are a diverse group of fungal decomposers which contribute to this process. 2. In field surveys of three pairs of impact-control stream sites we assessed the effect of eutrophication, mine pollution and modification of riparian vegetation on alder leaf breakdown rate in coarse and fine mesh bags and on mycelial biomass, spore production and species diversity of leaf-colonizing fungi. 3. In addition, we gathered published information on the response of leaf-colonizing fungi to these three types of perturbations. We conducted a meta-analysis of 23 published papers to look for consistent patterns across studies and to determine the relevance of four fungal- based metrics (microbial breakdown rate, maximum spore production, maximum mycelial biomass and total species richness) to detect stream impairment. 4. In our field surveys, leaf breakdown rates in coarse mesh bags were lower at impact than at paired control sites regardless of perturbation type. A similar trend was observed for leaf breakdown rates in fine mesh bags. Mycelial biomass and spore production were higher in the eutrophied stream than in the control stream. Spore production was depressed in the mine polluted stream, while it was slightly enhanced in the stream affected by forestry. Fungal diversity tended to be lower at impact than at paired control sites, though the mean and cumulative species richness values were often inconsistent. 5. Results of the meta-analysis confirmed that mine pollution reduces fungal diversity and performance. Eutrophication was not found to affect microbial breakdown rate, maximum spore production and maximum mycelial biomass in a predictable manner because both positive and negative effects were reported in the literature. However, fungal species richness was consistently reduced in eutrophied streams. Modification of riparian vegetation had at most a small stimulating effect on maximum spore production. Among the four fungal-based metrics included in the meta-analysis, maximum spore production emerged as the most sensitive indicator of human impact on streams. 6. Taken together, our findings indicate that human activities can affect the diversity and functions of aquatic hyphomycetes in streams. We also show that leaf breakdown rate and simple fungal-based metrics, such as spore production, are relevant to assess stream condition

Soil biota in boreal urban greenspace : Responses to plant type and age

Plant functional type influences the abundance and distribution of soil biota. With time, as root systems develop, such effects become more apparent. The relationship of plant type and time with the structure and abundance of soil microbial and invertebrate communities has been widely investigated in a variety of systems. However, much less is known about long-term soil community dynamics within the context of urban environments. In this study, we investigated how soil microbes, nematodes and earthworms respond to different plant functional types (lawns only and lawns with deciduous or evergreen trees) and park age in 41 urban parks in southern Finland. As non-urban controls we included deciduous and evergreen trees in 5 forest sites. We expected that microbial biomass and the relative abundance of fungi over bacteria would increase with time. We also expected major differences in soil microbial and nematode communities depending on vegetation: we hypothesized that i) the presence of trees, and evergreens in particular, would support a greater abundance of fungi and fungal-feeding nematodes over bacteria and bacterial-feeding nematodes and ii) the fungi to bacteria ratio would be lowest in lawns, with deciduous trees showing intermediate values. In contrast to our predictions, we showed that old deciduous trees, rather than evergreens, supported the highest fungal abundances and fungal-feeding nematodes in the soil. Consistent with our predictions, microbial biomass in urban park soils tended to increase with time, whereas - in contrast to our hypotheses - fungal-feeding nematode abundance declined. Even in the oldest parks included in the current study, microbial biomass estimates never approximated those in the minimally managed natural forests, where biomass estimates were three times higher. Anecic earthworm abundance also increased with time in urban parks, whereas abundances of fungal-feeding, plant-feeding and omnivorous nematodes, as well as those of epigeic and endogeic earthworms remained constant with time and without any distinct differences between urban parks and the control forests. Our findings highlight that although urban park soils harbor diverse soil communities and considerable microbial biomass, they are distinct from adjacent natural sites in community composition and biomass.Peer reviewe

Isolation and Characterization of Plant Growth Promoting Rhizobacteria from Ipomoea sp. Rhizospheres Growing in Iron Sand Soil

Iron  sand  field,  is  mostly  found  along  the  Indonesia  coast. It has  low  organic  matter, contains 38-59% iron (Fe) and sand particles. These characteristics can be called as extreme environments, however there are bacteria capable of growing and surviving in such habitats. Several genera are known as PGPR agents  such as Rhizobium, Azospirillum, Azotobacter and Pseudomonas. The research objectives were to measure total population of bacteria from rhizosphere of Ipomoea sp. in iron sand soils, to investigate the ability of bacterial isolates capable of fixing nitrogen, solubilizing phosphate, and producing plant growth hormone such as IAA, and to identify plant growth promoting rhizobacteria isolated from plant rhizospheres candidates growing in iron sand soils. Isolation on NA medium showed that the population were ranged from 1.59 x 105 to 5.2 x 105 CFU.g-1. There were 22 bacterial isolates originated  from the media of Ashby, Caceres, and Pikovskaya. Six isolates (A4, A10, C10, P2, P3, and P4) showed high ability to fix nitrogen, solubilize phosphate, and produce IAA. Isolate P4 grew in nitrogen fixing and phosphate solubilizing assay as well as IAA producing. It showed high value of phosphate index (275 mm). Bacterial identification indicated that four isolates (C10, P2, P3, P4) were species members of genus Bacillus and two isolates (A4, A10) were identified as species members of Actinomycetes.</jats:p

Isolation and Characterization of Plant Growth Promoting Rhizobacteria from Ipomoea sp. Rhizospheres Growing in Iron Sand Soil

Iron&nbsp; sand&nbsp; field,&nbsp; is&nbsp; mostly&nbsp; found&nbsp; along&nbsp; the&nbsp; Indonesia&nbsp; coast. It has&nbsp; low&nbsp; organic&nbsp; matter, contains 38-59% iron (Fe) and sand particles. These characteristics can be called as extreme environments, however there are bacteria capable of growing and surviving in such habitats. Several genera are known as PGPR agents&nbsp; such as Rhizobium, Azospirillum, Azotobacter and Pseudomonas. The research objectives were to measure total population of bacteria from rhizosphere of Ipomoea sp. in iron sand soils, to investigate the ability of bacterial isolates capable of fixing nitrogen, solubilizing phosphate, and producing plant growth hormone such as IAA, and to identify plant growth promoting rhizobacteria isolated from plant rhizospheres candidates growing in iron sand soils. Isolation on NA medium showed that the population were ranged from 1.59 x 105 to 5.2 x 105 CFU.g-1. There were 22 bacterial isolates originated&nbsp; from the media of Ashby, Caceres, and Pikovskaya. Six isolates (A4, A10, C10, P2, P3, and P4) showed high ability to fix nitrogen, solubilize phosphate, and produce IAA. Isolate P4 grew in nitrogen fixing and phosphate solubilizing assay as well as IAA producing. It showed high value of phosphate index (275 mm). Bacterial identification indicated that four isolates (C10, P2, P3, P4) were species members of genus Bacillus and two isolates (A4, A10) were identified as species members of Actinomycetes